- Cu-mediated selective bromination of aniline derivatives and preliminary mechanism study
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A simple and efficient bromination of aniline, aniline derivatives, and analogs have been developed. Forty three examples were given and the highest yield reached was 98%. Different substrates including substituted aniline, pyridin-amine, N-substituted aniline, N,N-disubstituted aniline, N-phenyl-amide, N-phenyl-sulfonamide, and nitrogen-containing heterocycles were all reactive and selectively generated desired bromo-products. The method can be applied to synthesize drug intermediate and quinoxaline derivatives.
- Zhao, Hong-Yi,Yang, Xue-Yan,Lei, Hao,Xin, Minhang,Zhang, San-Qi
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supporting information
p. 1406 - 1415
(2019/05/01)
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- Efficient and complementary methods offering access to synthetically valuable 1,2-dibromobenzenes
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1,2-Dibromobenzenes are highly valuable precursors for various organic transformations, in particular, reactions based on the intermediate formation of benzynes. This report describes short sequences for the synthesis of various derivatives based on regioselective bromination, ortho-metalation, and halogen/metal permutations. 1,2-Dibromo-3-iodobenzene (2f), 1,2-dibromo-4- iodobenzene (4c), and 2,3-dibromo-1,4-diiodobenzene (5e) act as intermediates in these syntheses. Bromo-iodoarenes have been synthesized by short and regioselective bromination or iodination sequences that combine ortho-metalation, halo-desilylation, diazotation, or bromination reactions of anilines. These polyhalo derivatives were then used as key intermediates to access a wide range of functionalized 1,2-dibromobenzenes by chemoselective organometallic reactions. Copyright
- Diemer, Vincent,Leroux, Frederic R.,Colobert, Fracoise
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experimental part
p. 327 - 340
(2011/02/26)
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- Electrophilic bromination of meta-substituted anilines with N-bromosuccinimide: Regioselectivity and solvent effect
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N-Bromosuccinimide-mediated electrophilic aromatic bromination of a series of anilines substituted with an electron-with-drawing group in the meta position was investigated. The regioselectivity of the reaction is markedly dependent on the polarity of the solvent and the bromination reaction can be tuned by appropriate selection of the reaction medium. Georg Thieme Verlag Stuttgart.
- Bartoli, Sandra,Cipollone, Amalia,Squarcia, Antonella,Madami, Andrea,Fattori, Daniela
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experimental part
p. 1305 - 1308
(2009/12/24)
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- Benzooxazole and benzothiazole antagonists of gonadotropin releasing hormone receptor
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The present invention relates to Gonadotropin Releasing Hormone (GnRH, also known as Luteinizing Hormone Releasing Hormone) receptor antagonists.
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Page/Page column 30; 41
(2008/06/13)
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- 7′-Substituted benzothiazolothio- and pyridinothiazolothio-purines as potent heat shock protein 90 inhibitors
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We report on the discovery of benzo- and pyridinothiazolothiopurines as potent heat shock protein 90 inhibitors. The benzothiazole moiety is exceptionally sensitive to substitutions on the aromatic ring with a 7′-substituent essential for activity. Some of these compounds exhibit low nanomolar inhibition activity in a Her-2 degradation assay (28-150 nM), good aqueous solubility, and oral bioavailability profiles in mice. In vivo efficacy experiments demonstrate that compounds of this class inhibit tumor growth in an N87 human colon cancer xenograft model via oral administration as shown with compound 37 (8-(7-chloro-benzothiazol-2-ylsulfanyl)-9-(2-cyclopropylamino-ethyl) -9H-purin-6-ylamine).
- Zhang, Lin,Fan, Junhua,Vu, Khang,Hong, Kevin,Le Brazidec, Jean-Yves,Shi, Jiandong,Biamonte, Marco,Busch, David J.,Lough, Rachel E.,Grecko, Roy,Ran, Yingqing,Sensintaffar, John L.,Kamal, Adeela,Lundgren, Karen,Burrows, Francis J.,Mansfield, Robert,Timony, Gregg A.,Ulm, Edgar H.,Kasibhatla, Srinivas R.,Boehm, Marcus F.
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p. 5352 - 5362
(2007/10/03)
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- Heterocyclic topoisomerase poisons
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The invention provides a topoisomerase poison of formula I: wherein R1-R8 have any of the meanings defined in the specification, or a pharmaceutically acceptable salt thereof, as well as pharmaceutical compositions comprising a compound of formula I or a salt thereof, intermediates useful for preparing a compound of formula I, and therapeutic methods comprising administering a compound of formula I or a salt thereof.
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- Bromination of anilines in superacids
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In HF-SbF5, bromination of aniline at -40 deg C by Br2 ( 0.6 equivalent) yields monobromoderivatives 2a (3percent), 2b (24percent) and 2c (50percent), the electrophile reacting on the anilinium ion.These percentages reflect the relative reactivities in the ortho, meta and para positions, no isomerization occuring either in the intermediate arenium ions or in the products.At room temperature, the products equilibrate (2a/2b/2c: 3/50/47), the process being intramolecular and proceeding by 1,2 Br shifts.Dibromation of aniline (Br2/substrate: 1.2 equivalent) gives compounds 3a (10percent) and 3b (55percent), the second bromination being controlled, in the corresponding anilinium ion, by the first introduced atom.In similar conditions toluidines 4a and 5a yield bromoderivatives 4b (80percent) and 5b (47percent), respectively.
- Berrier C.,Jacquesy, J. C.,Renoux, A.
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- Synthesis of Mercapturic Acid Derivatives of Putative Toxic Metabolites of Bromobenzene
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The synthesis and characterization of nine isomerically defined S-arylmercapturic acids of interest in connection with the metabolism of the model hepatotoxin bromobenzene is described.Included are three S-(bromophenyl)-, two S-(bromohydroxyphenyl)-, and three S-(bromodihydroxyphenyl)mercapturic acids of defined substitution pattern.In addition, several related compounds with two or no bromine atoms are described.These syntheses depend on two basic methods, 1,4-addition of various arene thiols to acetamidoacrylic acid or the 1,4-addition of N-acetyl-L-cysteine to various benzoquinone derivatives.In addition, we describe a method for efficient conversion of the mercapturic acids to thioanisole derivatives, regioisomers of which can be separed and detected at low levels by capillary gas-liquid chromatography.
- Hanzlik, Robert P.,Weller, Paul E.,Desai, Jayant,Zheng, Jiang,Hall, Larry R.,Slaughter, Donald E.
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p. 2736 - 2742
(2007/10/02)
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- Rates and Regioselectivities of the Palladium-Catalyzed Ethynylation of Substituted Bromo- and Dibromobenzenes
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The Pd(0)/Cu2Br2-catalyzed ethynylation of 1,2-dibromo-4-nitro- and 1,2-dibromo-3-nitrobenzenes provide rapidly the product in which the bromine para or ortho to the nitro group is displaced, whereas the corresponding dibromoacetamidobenzenes provide the product of meta displacement slowly.Investigation of the rates of a series of para-substituted bromobenzenes indicates that the reaction is zero-order with respect to the heptyne and bromobenzene concentration, with a Hammett ρ value of 2.8.
- Singh, Rina,Just, George
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p. 4453 - 4457
(2007/10/02)
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- Copper(I)-Induced Bromo-Hydrogen Exchange of 2,3-Dibromoanilines
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The copper(I)-induced bromine-hydrogen exchange reaction of 2,3-dibromoaniline and 5-substituted 2,3-dibromoanilines in the 2-position has been kinetically studied in water-acetic acid-hydrochloric acid medium at 90 deg C.The dehalogenation reaction is of second order, first order in both substrate and Cu+, and may be interpreted as a reductive substitution, composed of two one-electron steps.The 2,3-dibromophenol was only qualitatively investigated, but gave similar results.
- Liedholm, Brita
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p. 877 - 884
(2007/10/02)
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- 4- and 5-Substituted 2,3-dihydro-1H-isoindoles, pharmaceutical compositions and method of inhibiting phenylethanolamine N-methyltransferase
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Pharmaceutical compositions and methods of inhibiting phenylethanolamine N-methyltransferase using novel 2,3-dihydro-1H-isoindole compounds having 4- and 5-substituents.
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